Vehicles have been driven by many types of wheels, the basic "round" wheel has been known almost since the beginning of civilization. Variations of multiple wheels have been utilized in an endeavor to provide propulsion including rollers or annular shaped wheels in pairs or multiples. From the prior art discovered, the use of a disc that revolves thereby providing the propulsion means for moving a platform has been lacking.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention however, the following U.S. patents were considered related:
______________________________________ PATENT NO. INVENTOR ISSUED ______________________________________ 4,733,737 Falamak 29 March 1988 4,519,466 Shiraishi 28 May 1985 4,237,990 La 9 December 1980 3,700,058 Kuwahara 24 October 1972 ______________________________________
Falamak teaches a drivable, steerable platform containing a number of wheel assemblies that are drivingly rotated and steered. The wheels are powered by a motor for unilateral steering and a separate motor with connecting shafts and gear trains drives the wheels to coordinate the steering and propulsion direction. The device may be turned 360.degree. thereby steering the platform. The preferred embodiment is housed in a hollow sphere allowing the platform to move about on radically uneven terrain or even climb steps up to a height equal to approximate one-half of the spheres diameter.
Shiraishi employs a pair of inclined annular or doughnut-shaped wheels having a partially spherical surface of rubber or other elastic material arranged at an angle relative to the surface on which the drive system operates. The wheels are both driven in rotation by motors or the like and a similar motor changes the tilt angle which causes an omnidirectional movement of the system. A follower unit is arranged to follow the movement of the wheels and allows support for the system and may be in the embodiment of a caster or the like. The driven body is supported either jointly by the drive wheels and followers or solely by the followers (casters). The purpose of the system is to provide omnidirectional 360.degree. movement simulating the ambulatory movement of a human being.
La utilizes three wheels disposed at the corners of a triangle with one of the wheels having an axis which is at an angle to the others such that the axis is parallel to the surface engaged by the rollers. No two-wheels are aligned or parallel to each other. Each wheel consists of a plurality of rollers rotating on their respective axis. The vehicle is therefore omnidirectional as every given set of wheel rotational speeds and directions produces only one possible vehicle motion with no conflict between wheels. The wheels are rotated by an electric motor or the like attached individually to each wheel. There is some bouncing as the wheels rotate from one roller to the other, however, the greater number of rollers, the less the bounce.
Kuwahara again uses a combination of three wheels on the periphery, however, a steerable drive wheel is located in the center. The three wheels are the caster type and swivel freely while the driving wheel extends below an imaginery plane of the casters, allowing the drive wheel to change direction of movement in response to changes in the manner in which the weight of the person riding on the car is distributed. A steering wheel is provided to change the direction of the drive wheel and a motor with a battery provides the rotational force to propel the vehicle. A grip wheel directly below the steering wheel provides a surface for riders to support themselves. It is indeed apparent that large surface rotating disks have not been employed in vehicles for propulsion even though the principle of shifting weight is known to control steering.